Load-bearing fabric



Jan. 13, 1942. B. L. WHITTIER 2,270,154

LOAD-BEARING FABRIC Filed July 2, 1940 2 sheets-sheet 1 Patented Jan. 11.", 1942 Application July 2, 1940, Serial No. 343,665

' 3 Claims. (01.139-383) This invention relates to an improved fabric.

One of the objects of the present invention is to provide an improved load-bearing fabric capable of alternately assuming laterally concave and fiat positions under load without distortion or disintegration. Another object is to provide a fabric with an inherent minimum lateral elongation, and a maximum longitudinal elasticity. A'

further object is to eliminate wear due to internal friction in a fabric by providing increased lateral and longitudinal pliabi1ity.. Another object is to provide a fabric having increased bulk and increased impregnability to rubber. A- further object is to provide such a fabric with a surface adapted to increase its bonding or gripping action on rubber or similar laminating materials.

Equally important objects will plainly appear from th detailed specification and drawings presented herewith in exemplification but not in limitation of the present invention, wherein like reference characters designate like parts in the drawings which represent diagrammatically in:

herent tendency for the warp threads to-spread out in use while the weft threads tend to loop over the warp threads. This imparts a so-called high crimp or transverse elasticity to the fabric and at the same time critically reduces or prevents its longitudinal elongation and elasticity. In other words the characteristics of the fiat weave fabric were just the reverse of the results Fig. 1 a perspective fragmentary view of both a fiat portion and a concave portion of a load .bearing fabric embodying the present invention together with views of magnified areas of each Fig. -3 a partially expanded view of a preferred embodiment of my improved fabric together with a combined transverse cross sectional-end-view thereof corresponding to one of the laminations shown in Fig. 2, and in a like manner;

Fig. 4 a modification of the structural principle of the fabric embodied in Fig. 3, and ina like manner;

Figs. 5, '6 and '7 further modifications of this principle. I

Prior fabrics were originally woven with a plain weave which is usually referred to in the industry as one up and one down, wherein all warp threads are separately drawn. However, this weave soon proved undesirable due to its unusual stiffness and lack of bulk, which materially reduced its effective life. Prior attempts also have been made to .correct these disadvantages by replacing the plain weave fabric with a standard fiat weave fabric which in the industry better results because a flat weave has the inone harness.

' drawn,

two. ends 2| separately drawn.

long sought in the industry. These desired results were first provided by the present invention.

An illustrative fragmentary perspective view of my improved load-bearing fabric Ill in actual use is shown in .Fig. 1 travelling in the direction designated by the arrows over the plain rollers H and .over the concavi'ng rollers [2 which causes a portion of the fabric ID to assume a laterally concave position approximately along the are at 38 as shown in Figs. 1 and 2. A magnified view of the concave portion I 4 is shown at It and a magnified view of a flat portion l5 of the fabric In is shown at H in Fig. 1.

A transverse. cross sectional view, 35 of a laminated load-bearing fabric I0 is shown in Fig. .2 comprising two layers of a preferred form fof fabric 36 which may be laminated into a twoply or multi-ply structure by the vulcanized rubber layer 31. In this view the weft or filler threads 39 are shown passing in alternation over and under two warp strands 2| separately drawn and three warp threads l3 drawn as one end in' A combined transverse cross sectional view 36 and partially expanded plan view of the fabric 30 is shown in Fig. 3 in which the warp threads l3 and 2| are positioned longitudinally in the directionof travel of the fabric as shown by the arrow.-

In a like manner, a modification 40 of the preferred fabric 30 is shown in cross section at 46 in Fig. 4 wherein two groups of three warp ends 23 are consecutively-drawn with each group of three warp ends drawn as one warp end in alternation with two singl ends 2| separately drawn.

'A further modification 50 is shown in cross section at 56 in a like manner in Fig. 5 wherein one group of three warp ends I3 is drawn as one warp end in alternation with four ends 4i separately Another modification 6B is shown in cross section 66 in a like manner in Fig. '6 where four groups of three warp ends 43 are separately drawn each group as one end in alternation with An additional modification 10 is shown in cross section at 16 in a like manner inFig. 6 wherein four groups of three warp ends 43 are consecutively drawn as one end in alternation with four warp ends 4| separately drawn.

It is preferred that the fabrics herein described have twelve to sixteen filling threads per inch and twenty-one to twenty-seven warp threads per inch. It is also preferred that the Weight of the warp threads therein be two to four times the weight of the filling threads, and that the diameter of the warp threads be from one and onehalf to two times the diameter of the filling threads.

Research has shown that fabrics made in accordance with the invention herein described are capable of a thirty-five to forty percent warp elongation at warp break of approximately five hundred pounds tensile stretch per inch of width. This has been accomplished not only without increasing the brittleness but has so reduced lateral elongation that it is practically non-existent. Furthermore, this has been accomplished with an increase in the softness and flexibility and thickness of the fabric which has also been provided with the added advantage of a resilient and reticular surface that not only improves the impregnating quality of the fabric but also increases its ability to maintain a se cure bond when laminated into a multi-ply structure.

From the foregoing it becomes apparent that the maximum longitudinal elongation and elasticity and the minimum lateral elongation in the fabric provided by the present invention permits such a fabric to repeatedly assume laterally concave and fiat positions when in use under effective load without distortion or disintegration of the fabric. These characteristics together with inherent bulk and softness of the structure add to the life and durability of the herein described fabric by reducing internal friction in the fabric. spread apart or away from each other but tend to become compressed together due to their greater size and strength (as compared to the weft threads) and their elastic response longitudinally to changing loads. This is diagram- Furthermore, the warp threads do not matlcally shown in the enlarged area at 16 in Fig. 1 wherein a concave portion of the fabric l0 under load is shown with the filler threads spreading away from each other, and in the enlarged area I! the filler threads are shown in their normal position when not underload.

An examination of Figs. 2 and 3 will illustrate the reticular bonding and impregnating surface provided by the improved fabrics herein described. It is thus apparent that an improved fabric embodying all of the long desired advantages heretofore unattained is provided by the present invention by including in a laminated structure one or more cotton duck or similar textile fabrics having structure that may be broadly defined as one in which the warp ends are drawn in such a manner that there will be multiple warp ends in one harness drawn as one end with adjacent warp ends separately drawn. This arrangement occurs throughout the width of the fabric 1 with the harness drawn ends and the separately drawn ends appearing alternately. Filler or weft threads materially smaller than the warp threads are passed in alternation over and under each group of harness drawn warp ends and alternately over and under each separately drawn warp end. While one to four groups of three ends thus drawn may be preferably alternated with from two to four ends separately drawn in the various combinations herein set forth, it is not intended to limit this invention thereto but only to the spirit and scope of the following claims.

What is claimed is:

1. In an improved load-bearing web structure, a fabric in which the warp threads are longitudi naily positioned with respect to said web structure, said fabric consisting of groups of multiple warp ends, the ends of each group lying in side by side contacting relationship throughout their lengths and woven as one warp end and Warp ends intermediate each pair of said groups each separately woven, and a filler thread materially smaller and lighter than said warp threads passed in alternation over and under each group of multiple warp ends and in alternation over and under each of said separately drawn warp ends.

2. The combination of claim 1, wherein said warp threads have an average weight of approximately three times the weight of said filling threads.

3. The combination of claim 1, wherein the warp and weft threads in said fabric possess a high degree of pliability, the longitudinal pliability in said fabric being at least equal to the transverse pliabilitytherein, whereby said fabric will have a warp elongation of at least approximately thirty-five per cent and a warp break of approximately five hundred pounds tensile strength per inch of width.

BENJAMIN L. WHI'I'IIER. 

